The invention relates to a magazine that serves to receive several fastening elements and held by elastic side members which pivot outwardly when the elements are driven.
DE-2 022 136 discloses a carrier that serves to receive and to guide several fastening elements arranged one behind the other and having a shaft and a head that project outwardly from the shaft in the radial direction. The magazine is made up of a support area from each of whose lengthwise edges a side area extends in the placement direction of the fastening elements. The free end areas of the two side edges are arranged adjacent to each other. Between the support area and the side edges, a chamber is formed that extends over the entire length of the carrier.
The entire magazine is divided into several receiving areas arranged one behind the other, each serving to receive one fastening element. The division is effectuated by means of cutouts that run essentially parallel to the placement direction of the fastening elements and that, starting from the free ends of the two side areas that touch each other, extend over a part of the side areas.
In the support area of each receiving area, there is an opening whose diameter is larger than the shaft of the fastening element and smaller than the head of the fastening element. Coaxial to this opening, there is a passage formed by the two end areas of the side areas whose diameter essentially matches the diameter of the shaft of the fastening element.
Since the head of the fastening element is situated in the chamber of the magazine, the element is guided mainly by the front section of the shaft on the side of the placement direction in the passage formed by the side areas.
The invention is based on the objective of creating a magazine with a carrier and several fastening elements, which is simple and cost-effective to manufacture, which ensures proper guidance of every single fastening element at two places on the shaft that are at a certain distance from each other, and with which the fastening elements are separated from the magazine without a need to exert much force.
In the magazine according to the invention, each fastening element is guided in the area of the shaft at two places that are spaced at a certain distance from one another. This guidance takes place with the opening in the support area and with the passage in the end area of the two side edges. Slits located in the support area divide the circumferential area of the opening into several circular ring segments that, during the placement process of the fastening element in the placement direction, can easily be pivoted down into the chamber of the magazine by means of the head of the fastening element or by means of a washer and/or shim mounted on the head and resting on the fastening element. After the head has traversed the opening, the outer contour of the head or of the washer and/or shim comes into contact with the inner surface of the two side areas, laterally expanding them so that the head or the washer and/or shim can leave the magazine without being hindered.
The head or the washer and/or shim of the fastening elements rests on the support area that is, for example, flat in shape, and thus on the outside of the magazine. So that this head can be pushed through the magazine without the expenditure of much force, it is necessary that the circular ring segments can easily be pivoted downwardly into the chamber of the magazine. To achieve this offset, preferably four slits are provided. With a larger number of slits, the length of the arc-shaped pivoting axis is reduced, thereby diminishing the resistance that counters the inward pivoting of the circular ring segments into the chamber.
Advantageously, the width of the slits increases as the distance from the opening increases. Thanks to this special shape of the slits, the arc-shaped pivoting axes of the circular ring segments that surround the openings are shortened so that these segments can be pivoted downwardly into the chamber with a smaller amount of force.
The length of the slits likewise has an influence on the pivoting behavior of the circular ring segments that surround the opening. For instance, the segments can be pivoted downwardly into the chamber more easily if the slits extend considerably beyond the outer contour of the head of the fastening element or washer and/or shim. Longer slits, with the fastening elements remaining at a constant distance from each other, can be achieved in that at least one slit running parallel to the lengthwise extension of the magazine as well as at least one slit running perpendicular to the lengthwise extension of the magazine are associated with a first opening, and slits running at an angle in the range of 30xc2x0 to 60xc2x0 with respect to the lengthwise extension of the magazine are associated with at least one adjacent opening.
An additional guidance of the fastening elements, with which the circular face of the head or of the washer and/or shim facing in the placement direction is convex or concave in shape relative to the placement direction of the fastening elements, can be achieved by means of the support surface. The support surface advantageously has a concave area or a convex area in the circumferential area of the opening.
For manufacturing-related reasons, the concave or convex areas preferably extend over the entire length of the carrier strip.
So that the magazine can be transported for example, in the transport mechanism of a tool by means of which the fastening elements can be inserted into a receiving material, the carrier strip advantageously has several transport means arranged one behind the other on which an advancing element of the transport mechanism can engage in a form-fitting manner.
So that a transport element of a transport mechanism can be brought into formfitting contact with the transport means of the magazine in a direction running parallel to the placement direction as well as perpendicular to the placement direction, preferably each of the transport means is formed by a recess situated in the lengthwise edges of the support surface. However, the transport means can also consist of individual boreholes arranged one behind the other in the support area, such boreholes being capable of interacting in a form-fitting manner with the advancing element of the transport element.
A center axis extending through the opening and the passage runs essentially perpendicular to the lengthwise extension of the magazine. This center axis, however, can also be arranged at an angle to the lengthwise extension of the magazine. This is especially the case if this magazine is not fed perpendicularly but rather at an angle to the placement direction into a tool with which the fastening elements can be inserted into an appropriate receiving material. The alignment of the cutouts is adapted, for example, to the position of the above-mentioned center axis in each case, i.e. the cutouts run essentially parallel to the center axis.
The carrier strip is made, for example, of a thin-walled polyester film. The thickness of this film is in the range of 0.15 mm to 1.5 mm. However, the carrier strip can also be made of a single-layer or multi-layered plastics material, paper, cardboard or sheet metal, the individual layers being joined to each other by means of adhesion, welding or compression. A carrier strip made of paper or cardboard can be provided, for example, with an impregnation against external influences, such as moisture or dirt in particular.
The slits are configured so as to be closed in the circumferential area of the opening. This closed area situated in the circumferential area of the opening consists of a small connection web that is destroyed during the placement process of the fastening elements, so that an unhindered pivoting of the circular ring segments into the chamber of the magazine is possible. The connection web ensures the uniform alignment of all of the circular ring segments before the placement process with the fastening elements.
Advantageously, the end areas of the elastic side members that are spaced from the opening are arranged at a certain distance from each other, the distance being smaller than the diameter of the shaft of the fastening element. This arrangement of the two end areas or parts has the advantage that, in the area of the shaft, the fastening element is guided by four edge areas of the passage formed by the two end parts, the edge parts being distributed linearly and essentially uniformly in the circumferential area of the shaft.
In order to be able to achieve a high dimensional stability, the end areas of the two side areas or members are advantageously connected to each other via a detachable, form-fitting connection.